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Commit 9404ef34 authored by Ivo van Doorn's avatar Ivo van Doorn Committed by John W. Linville
Browse files

rt2x00: Driver requiring firmware should select crc algo 



The driver should select what CRC algorithm is required
when performing a checksum on the firmware.

rt61pci & rt73usb require crc-itu-t
rt2800pci & rt2800usb require crc-ccitt

Legacy 2800pci/usb driver uses crc-itu-t + bit order reversion,
but that is just inefficient especially since the end result is
the same as a different algorithm which is also available as library. ;)

Signed-off-by: default avatarIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent adfdbb79

drivers/net/wireless/rt2x00/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ config RT2X00_LIB_USB 
config RT2X00_LIB_FIRMWARE

	boolean

	depends on RT2X00_LIB

	select CRC_CCITT

	select CRC_ITU_T

	select FW_LOADER

drivers/net/wireless/rt2x00/rt2x00.h

+2 −0
Original line number Diff line number Diff line
@@ -551,6 +551,8 @@ enum rt2x00_flags { 
	 * Driver features

	 */

	DRIVER_REQUIRE_FIRMWARE,

	DRIVER_REQUIRE_FIRMWARE_CRC_ITU_T,

	DRIVER_REQUIRE_FIRMWARE_CCITT,

	DRIVER_REQUIRE_BEACON_GUARD,

	DRIVER_REQUIRE_ATIM_QUEUE,

drivers/net/wireless/rt2x00/rt2x00dev.c

+3 −5
Original line number Diff line number Diff line
@@ -1017,11 +1017,9 @@ int rt2x00lib_start(struct rt2x00_dev *rt2x00dev) 
	 * If this is the first interface which is added,

	 * we should load the firmware now.

	 */

	if (test_bit(DRIVER_REQUIRE_FIRMWARE, &rt2x00dev->flags)) {

	retval = rt2x00lib_load_firmware(rt2x00dev);

	if (retval)

		return retval;

	}



	/*

	 * Initialize the device.

drivers/net/wireless/rt2x00/rt2x00firmware.c

+32 −9
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
	Abstract: rt2x00 firmware loading routines.

 */



#include <linux/crc-ccitt.h>

#include <linux/crc-itu-t.h>

#include <linux/kernel.h>

#include <linux/module.h>
@@ -37,7 +38,6 @@ static int rt2x00lib_request_firmware(struct rt2x00_dev *rt2x00dev) 
	char *fw_name;

	int retval;

	u16 crc;

	u16 tmp;



	/*

	 * Read correct firmware from harddisk.
@@ -64,17 +64,37 @@ static int rt2x00lib_request_firmware(struct rt2x00_dev *rt2x00dev) 
	}



	/*

	 * Validate the firmware using 16 bit CRC.

	 * The last 2 bytes of the firmware are the CRC

	 * so substract those 2 bytes from the CRC checksum,

	 * and set those 2 bytes to 0 when calculating CRC.

	 * Perform crc validation on the firmware.

	 * The last 2 bytes in the firmware array are the crc checksum itself,

	 * this means that we should never pass those 2 bytes to the crc

	 * algorithm.

	 */

	if (test_bit(DRIVER_REQUIRE_FIRMWARE_CRC_ITU_T, &rt2x00dev->flags)) {

		/*

		 * Use the crc itu-t algorithm.

		 * Use 0 for the last 2 bytes to complete the checksum.

		 */

	tmp = 0;

		crc = crc_itu_t(0, fw->data, fw->size - 2);

	crc = crc_itu_t(crc, (u8 *)&tmp, 2);

		crc = crc_itu_t_byte(crc, 0);

		crc = crc_itu_t_byte(crc, 0);

	} else if (test_bit(DRIVER_REQUIRE_FIRMWARE_CCITT, &rt2x00dev->flags)) {

		/*

		 * Use the crc ccitt algorithm.

		 * This will return the same value as the legacy driver which

		 * used bit ordering reversion on the both the firmware bytes

		 * before input input as well as on the final output.

		 * Obviously using crc ccitt directly is much more efficient.

		 */

		crc = crc_ccitt(~0, fw->data, fw->size - 2);

	} else {

		ERROR(rt2x00dev, "No checksum algorithm selected "

		      "for firmware validation.\n");

		retval = -ENOENT;

		goto exit;

	}



	if (crc != (fw->data[fw->size - 2] << 8 | fw->data[fw->size - 1])) {

		ERROR(rt2x00dev, "Firmware CRC error.\n");

		ERROR(rt2x00dev, "Firmware checksum error.\n");

		retval = -ENOENT;

		goto exit;

	}
@@ -96,6 +116,9 @@ int rt2x00lib_load_firmware(struct rt2x00_dev *rt2x00dev) 
{

	int retval;



	if (!test_bit(DRIVER_REQUIRE_FIRMWARE, &rt2x00dev->flags))

		return 0;



	if (!rt2x00dev->fw) {

		retval = rt2x00lib_request_firmware(rt2x00dev);

		if (retval)

drivers/net/wireless/rt2x00/rt61pci.c

+2 −1
Original line number Diff line number Diff line
@@ -2258,9 +2258,10 @@ static int rt61pci_probe_hw(struct rt2x00_dev *rt2x00dev) 
	rt61pci_probe_hw_mode(rt2x00dev);



	/*

	 * This device requires firmware

	 * This device requires firmware.

	 */

	__set_bit(DRIVER_REQUIRE_FIRMWARE, &rt2x00dev->flags);

	__set_bit(DRIVER_REQUIRE_FIRMWARE_CRC_ITU_T, &rt2x00dev->flags);



	/*

	 * Set the rssi offset.